A large extinct flightless auk (seabird) of the North Atlantic, resembling a giant razorbill. The great auk was the original ‘penguin’; many were taken for food, and the last individuals were killed on an islet off Iceland in 1844

A group of five large interconnected lakes in central North America, consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, and constituting the largest area of fresh water in the world. Lake Michigan is wholly within the US, and the others lie on the Canada-US border. Connected to the Atlantic Ocean by the St Lawrence Seaway, the Great Lakes form an important commercial waterway

A circle on the surface of a sphere which lies in a plane passing through the sphere’s centre. As it represents the shortest distance between any two points on a sphere, a great circle of the earth is the preferred route taken by a ship or aircraft